Deep Space Exploration
by teaandcharcoalforbreakfast
Summary: John wants a little hands-on experience with troll anatomy. Karkat is (secretly) happy to oblige. Johnkat PWP.


"A-are you sure about this?" John asked, voice shaking. He was blushing so hard his whole chest was pink.

"I wouldn't have fucking suggested it if I wasn't sure!" Karkat spat.

"Yeah, well, I _thought _I was sure. Now I- I guess I'm just nervous."

"You are completely undisturbed about facing almost certain death, but the idea of your creator, who has occasionally accidentally picked inopportune times to watch you and has also been your human matesprit boyfriend thing for perigrees now, seeing your bulge frightens you. Jesus fuck, John, stop being such a wriggler."

"But I've never done this before…"

"Look, I'm not asking you to fill a pail with me, dumbfuck. You're the one who came over here and started fondling my grub-stripes. And unlike you I have no need to fondle bizarre pieces of biology. Although I still don't understand why you have milk holes that don't make milk."

John winced, "Please don't call my nipples that."

"Whatever. And you said, I quote, 'Sure, because your alien dong has to be completely normal.' Which it fucking is, but you wouldn't believe me."

John glared at him self-righteously but Karkat just rolled his eyes. He wouldn't have been in that situation if it weren't for the damn semi-public bathrooms. They'd been perfectly happy with the chaste state of their relationship earlier, god knowing that human and troll anatomy weren't all that compatible (Rose and Kanaya had no problem, but John had the wrong half for their kind of coupling).

Anyway, Karkat was just getting out of the shower, wearing nothing but a towel, and john was in the same state on his way in. Given, Karkat had also felt curiosity, the urge to touch just to know what it was like, when he first saw a human shirtless. But like hell he was going to ask Strider if he could cop a feel, so he'd quelled it. John, however, seemed to lack that ability.

Besides, having those long, dexterous fingers stroking his sides and belly made Karkat's bone sheath all but swing open.

"Alright," John said nervously, "On three. One… two… Three!"

They both let their towels fall to the ground. Karkat couldn't help but gawk. It was just _there. _Sitting completely exposed and vulnerable except for a covering of scraggly hair and what the _fuck _was that supposed to do to protect it? And then in spite of John being shocked to learn that trolls had "both," it looked like he had egg pouches too, but they also hung free with no bone or nook to protect them. Sure, he'd seen Dave's crude drawings, but they didn't capture the alien vulnerability of the real thing. Then, to his surprise, John started laughing.

"The fuck is so funny, Egderp?"

"You look like a ken doll!"

"A what?"

"My god, you don't have _anything!" _

Karkat blushed, "Just because not everyone lets theirs flop around doesn't mean we don't have it!" He gestured to the reddish lines at the juncture of his pelvis and thighs.

"What's that?" John asked, curiosity returning to his eyes.

"It's the edge of the font piece of my bone sheath."

"I wanna see."

"What?"

"Please, Karkat?"

Karkat nibbled his lip. Was this a normal part of human courtship? He'd learned that human relationships were a bizarre blend of moirail and matesprit, but he was still unsure where various lines were. But if John wanted to do it it was probably okay? Besides, there was no denying that Karkat wanted him to. Before he really understood human anatomy, he'd wondered about tangling bulges with his new boyfriend and he couldn't deny that he wanted to come undone under John's touches.

"Fine."

He tugged John back into one of the stalls in case anyone walked in on them.

"Alright, here." He sat on the ground and spread his legs.

John knelt between them, staring intensely. Karkat could feel the blood rushing south, the lining of his sheath turning even bolder. To another troll that would be an obvious sign saying "Just fucking pail me already!" John just stared.

"So is it three pieces, then? A left, a right, and a front?"

"Yes." Karkat said, silently begging John to just fucking _touch _already.

John looked up. "Dude, how do you pee?"

"Fucking- Egbert, why the _fuck _are you asking at a time like this?"

"I donno, it's just weird."

And now the shitstain wouldn't go on until he knew. "Not every species leaks like you do, goddammit." Although Karkat thought it was quite the accomplishment he wasn't dripping a different sort of liquid at the moment.

"Weird. But I guess even on earth birds don't. So, anyway, how does it-?"

"You have to touch it."

John reached out with one hand, oh so gently, and traced the seam.

"Wow, you're soft he- Holy shit!"

Karkat had swung open almost immediately and John pulled back like he'd been stung. Karkat's bulge reached out, wanting to lean into the boy's touch. And there was the leaking. All the juices that had built up came running out and he was _so _glad he was sitting in a shower.

"That- that's a little closer to what I expected."

Karkat gave John's equipment one more look. No wonder he was taken by surprise, it was rather different. Instead of one droopy bit, Karkat's bulge was made of several long, prehensile tentacles, all bright red and leading right into his equally red nook. He wondered if all the red was confusing John, if he couldn't see the slight differences that any troll knew by instinct. Right now both his bulge and nook were moving, though the former was much more aggressive in looking for corresponding piece John just didn't have.

"How- how many are there?"

"Four. That- that's how it's easy to tell I'm a mutant and not just a rustblood. Otherwise I'd only have one."

"So the number of dicks you have corresponds to blood caste?"

"Yes."

He scrunched his nose. "That's weird. But then-" When he looked up at Karkat he was a deeper red than before. "Can I- can I touch?"

Karkat's breath caught, "Oh _fuck _ye- I mean, I guess it's okay."

John beamed down at him and reached out. This time Karkat's bulge latched on to him automatically, running over his fingers. And then, to Karkat's surprise, the idiot _laughed. _

"Hey, I think it likes me!"

"John, _it _is a piece of my anatomy that reacts on pure instinct without consulting me first. It- It thinks you're a very poorly endowed blueblood."

"Is that what it's doing? Looking for a nook?"

"Yeah, but-" John moved his fingers slightly, making Karkat moan out loud. "Soon it'll decide you're probably my kismesis and give up, thinking you left your other flaps closed."

"Ha ha! That's so cool, Karkat! I- oh!"

Karkat's bulge wrapped harder around John's fingers and started massaging them. For a moment John just stared. Then he let out a soft moan of his own and began rubbing back. Karkat threw his head back and bit his lip so hard it bled_. _He'd never had someone else touch his bulge, and the soft, complex swirls on John's fingertips were doing wonderful things. Then it was gone as John slipped away.

"What the fuck? Jesus, John, bring your shitty hand back here!"

"I was wondering- wondering if we can try something?"

"_Why?!" _

"W-well, I-" He looked away, Karkat looked down and saw the way John's bulge had grown and stiffened. It twitched as Karkat's eyes landed on it, a drop of whitish genetic material falling.

"That… That is not as pathetic as I thought."

"I was wondering, your nook looks so small and tight and I-"

Karkat took a deep breath and looked at the organ. "How much control do you have over that thing?"

"Not much."

"Then no. Kanaya told me human nooks-"

"Vaginas."

"Whatever. –Are built to take a beating. From those, presumably. We need dexterity, gentleness, which is why you don't let your kismesis touch it."

"Oh." He looked painfully put out.

"Okay, look, I'm not just leaving you out in the cold, Egbert. Come up here."

He nodded and crawled forward until they were almost kissing. Then Karkat's bulge reached out and wrapped around his cock.

"Shit-!" John choked out.

Karkat smiled and pet John's hair. His cock was thick, ridged, and all together not as fun to wrap around as his fingers, but it was warmer and the hair and loose skin was almost as interesting. And _oh _was the view lovely. John's face was completely screwed up: big beautiful teeth biting his lower lip, eyebrows furrowed, eyes shut tight. And _fuck _he was so pink, his candy-red blood rushing to the surface and making Karkat feel unbelievably protective.

"_My species. My blood. My matesprit. MINE!" _

John groaned as one of Karkat's tentacles reached back, exploring further. He opened his eyes to look at Karkat drunkenly.

"Are you okay?" Karkat asked.

"Yeah. Awesome. Man, you got the memo about fondling the balls without me even telling you."

Karkat didn't understand what that meant, and he wasn't really listening anyway. He was focused on those thin lips and how much he wanted those too. He grabbed John's hair and yanked him down, tangling their tongues. Another tentacle detached from John's cock, sliding even further back and, oh, it must have _known _that wasn't a nook but didn't seem to care as it slid into John.

"Oh, woah!"

Shit, fuck, that's right. John had told him he didn't want his waste-chute involved. Using an immense amount of willpower, Karkat managed to override his instincts and reel his bulge back in.

John looked up, "Why'd you stop?"

"You told me you didn't want-"

"I was wrong. It happens. Kind of a lot, if you hadn't noticed. Especially about this stuff. Because that was fucking _awesome." _

Karkat rolled his eyes. "You could have said that earlier, dumbfuck."

"Yeah, well. Since we've stopped, if you get ass privileges I want nook privileges."

Karkat eyed those long, dexterous fingers that were currently resting on his chest before nodding. God, how long had he dreamed of those sliding inside of him? His nook was more sensitive than his bulge, and John's hand had already felt so good on that… "Not the bulge, though."

"Got it."

John gave him a kiss on the nose that was far too cute for the situation and then slid down his body. Karkat spread his legs a little wider so John could fit. A cool hand landed on Karkat's thigh. John's eyes were locked onto his nook, looking absolutely reverent. Oh, that damn bulge! Karkat threw his hand down to catch it before it decided to try using John's hair as a bucket. But damn if that wasn't a hot image- John covered in Karkat's genetic material: red dripping everywhere, the way he would innocently look at it, maybe even wipe some off his cheek with his finger and reach out his oh-so-lovely tongue to-

But even that fantasy wasn't as good as when that same tongue actually reached out to taste his nook. And he'd thought lightning up the spine was poetic language.

John made a startled noise. "You're sweet," He said.

"Thanks? Why would you say that at a time like this?"

"No, I mean your nook," He gave it a long swipe, which made Karkat shudder and squeeze his bulge more tightly to keep it from escaping. "It's so sweet."

He dove in more deeply, but it was still such a _tease. _No troll was that short, and the flexibility of John's tongue was making Karkat's nook think it was the tip of a particularly sadistic bulge. And it was just exploring and tasting, not fucking, not rubbing the sweet spots. He was trying to pull it in with all he had, feeling so _empty _now. John wormed his finger in beside his tongue: stiff and not as slick, but longer and more powerful. And _God, _it was stroking him so deeply. Karkat wanted more: he needed it thicker, pressing harder. John slid another finger in, just a little bit longer than the first. Karkat squirmed, torn between wanting to get away from the slight stretch and begging for another. Then John moved his fingers apart and Karkat knew what his choice had to be.

"More." He breathed.

John hummed an affirmative, making Karkat shiver, but then pulled his mouth away.

"Egbert, the fuck do you think you're doing? Get back here!"

"Shhh," John said, stroking Karkat's thigh with the hand that wasn't several inches deep in nook. "I'm giving you more."

He slid his third finger in next to its brothers, and Karkat swore he was ripping near the base. But, fuck if it didn't feel good. He keened, rutting down to look for more inches that just weren't there. John spread his fingers and Karkat yelped.

The asshole giggled again, "You're so cute, kitty."

"So help me, Go- ah!"

He'd crooked his fingers in just the wrong (right) way, and no matter how good it was Karkat had to grab his wrist.

"What's wrong?"

"N-not there. Anywhere else."

"Sorry!" John pulled out.

"No, wait!"

"Look, if it hurts you-"

"It didn't hurt. It's my-" He paused. He didn't know how John would feel about what it really was. "I'll tell you later. For now…" He flipped them.

"Ah! Karkat! What are you-"

"I told you, I want more."

"What do you-"

Karkat leaned down and kissed him. John purred into the kiss, reaching up and rubbing the sensitive skin around his horns. Oh, that was nice. And, _shit, _he tasted like nook and it was _Karkat's _nook and he wanted to keep kissing him forever and ever, but his nook just felt so empty and his bulge was reaching out again. Karkat peeled himself off.

"Against the fucking wall."

John nodded eagerly and moved so fast he hit his head with a resounding thud.

"Are you-"

"I'm fine! Fine! Just, come on, Karkat!"

Karkat slid onto his thighs. "Okay, alright, so I know I said it wouldn't work, but I think that maybe if I'm up here we'll be okay because oh, fuck, Egbert, I need that weird alien bulge of yours right now or I am going to fucking implode from how empty my nook is and I need-"

John leaned forward and kissed him again. When he pulled away he smiled almost comfortingly.

"Word vomit."

"Yeah, yeah I know," Karkat muttered. He looked down at John's bulge, still sitting straight up and doing that weird twitching thing and dear _god _what the _fuck was he thinking?! _

"It's okay," John said softly.

"I know."

"Sure."

"Alright, okay, let's-"

"Karkat."

"For the love of _God, _Egbert, what?!"

"I love you."

Karkat looked up and John just looked so damn pathetically adorable, wide eyes and adoration that was way too innocent to have a face smothered with Karkat's slick. God, Karkat was pretty sure his ever-increasing blush was inventing new shades of red at this point, but he smiled back sheepishly anyway and finally got around to actually touching John's- John groaned and tipped his head back.

"From just that?" Karkat asked, smirking.

"No, from you teasing me for this long and imagining how good you're gonna feel."

"Y-yeah."

John began gently stroking Karkat's horns. "It's supposed to be easier if you relax."

"Mm-hmm."

John's other hand landed on Karkat's hip and helped lower him. And then, _fuck, _what was the fucking point of having such a fat part on the top anyway? And it was so blunt! There was no good way to really ease in, not like the nice taper that came with normal bulges. But after the first part it got all the easier. John just slid in easily after that until Karkat was sitting on his lap.

"You're so tight!" John hissed.

"Better than your hand, huh, Egbert?"

"_So _much better."

Karkat laughed. "You- you're better too."

"I'm ready whenever you are."

"Ready? For what? My bulge can't reach you like this."

"Um? Moving? Do trolls do that?"

"Well, normally your bulge would sort of move around on its own."

"Oh," John looked down. "Usually humans, well…" He lifted his hands and made a gesture that probably was obscene in human culture.

"Oh."

"Yeah."

"We can try, I mean, maybe if I just-" Karkat braced his hands on the floor and carefully lifted himself just a little bit.

John's reaction was immediate, letting out a high-pitched whine as he slid against every inch of Karkat's nook that was desperately trying to keep him right where he was (the rest of Karkat wanted him there too, but…). He tried playing with the angles, hoping to figure out what worked the best, felt the most natural.

John grabbed him by the horns and yanked him forward, smashing their lips together. Karkat let his eyes fall closed as he returned the kiss, opening his mouth to play with tongue and teeth. It was messy, even though they were both far more practiced at that part. But it didn't matter that the angle was weird and the kiss was sloppy, and that this bulge was so weird and _wrong, _because it was John, and that made everything okay.

One of John's hand, warm and sweaty, slid down to tangle with his bulge again. Karkat gasped into John's mouth.

"Tha- that's better. Come on, Kitty. I'm almost there."

"D-do you have a bucket?"

"No. On me."

"John!"

"It's okay, we're in a shower stall. You can make a mess. Besides, might be fun!"

Karkat stopped moving. "John Egbert, you are one of the kinkiest bulge-lickers in all of paradox space."

John laughed and teased his bulge, making Karkat roll his hips up against him. He choked mid-laugh and started making these weird little bucking movements.

"Ah, Jesus, Karkat!"

He didn't feel a stream of genetic material, but his expression and movements couldn't help but make him wonder. "Wait, wait, are you _coming? _I swear to God, John, if you are using me as your bucket right now-!"

John opened his eyes and smiled. "Sorry, it- it snuck up on me."

"Oh, oh that is just so _wrong! _It's disgusting! Fuck, Egbert, I-"

But then John gave him the most perfect little squeeze that made Karkat spill too, making him look like a total idiot.

"Sneak up on you too?" He asked, running his fingers over his dripping red stomach.

"Fuck you, Egbert."

"Maybe next time," John said, kissing his shoulder.

"We should move," Karkat said.

"Probably. But, God, it feels so good inside you."

"God, Egbert!"

"What? It does. You're warm." He kissed one of Karkat's cheeks. "And soft." And then the other. "And I'm tired." He gave him a chaste little kiss on the lips, like they hadn't just used one another as their personal buckets.

"I did all the fucking work," Karkat mumbled, setting his cheek on John's shoulder.

"We should do this again," John said. "Tonight. In a bed. So we can just sleep cuddled up together and stuff after."

"That sounds… pretty good, actually."

"And maybe I could try actually being a bulge-licker."

If Karkat wasn't so spent he'd be ready to go again at that. As it was, his bulge was sheathing itself again, and his nook wanted to close up too. He lifted himself for a moment to allow the bone to shut before sitting back down on John's lap.

"So is that what it looks like when you're not interested?"

"Gray and boring?"

"Well, gray at least. Oh yeah! You wanna finish my anatomy lesson now?"

"With what?"

"What was wrong with that one place?"

"It's my egg pouch. If you touch it too much it'll activate and we'll have a bucket full of slimy mutant eggs in a week or two."

John hissed through his teeth, "Sorry."

"It's not a big deal. It's more about how I would feel crabby and bloated until they come out."

"Huh. That's kind of cool, actually!"

"Cool?"

"Yeah! Human girls just kind of make one a month or something? I don't know all of the details."

"That sounds like a huge waste."

"I donno. You're the one who made us."

Karkat stood and offered John a hand. "Whatever, let's wash this shit off."

"I'd love to."

As John washed his back Karkat realized for the first time that he didn't feel ashamed of himself: of his blood, or his scars, or his scrawny form, or even his personality. He leaned back into John's touch and for once just let himself just be happy.


End file.
